Each year roughly 200,000 U.S. women undergo a surgery to repair pelvic organ prolapse (6, 7). Biologic and synthetic meshes are widely used in prolapse repairs to improve anatomical outcomes over native tissue repairs which currently have a failure rate of over 30%. To date, however, there is little scientific data to guide surgeons in the selection of a particular product. As a result, meshes are used based on the recommendations of a local vendor and consequently, are placed in women on a trial and error basis. There is growing evidence, however, that the complications associated with prolapse meshes cause unacceptably high rates of morbidity including infection, mesh shrinkage, mesh erosion, mesh exposure, pelvic, rectal and bladder pain and dyspareunia. Such complications have become significant enough for the FDA to recently release a warning about mesh use, especially when it is placed transvaginally. In this proposal, we therefore, aim to establish an interdisciplinary team of scientists dedicated to the comprehensive testing of previously or newly marketed prolapse meshes and for the development of the next generation of graft materials based on specific scientific criteria. In the first phase of the study, we determine how biochemical and structural changes in the prolapsed vagina impact passive and active mechanical behavior so as to develop a mesh in which these deficiencies are repaired or compensated for, allowing us to restore the prolapsed vagina to the nonprolapsed condition. In the second phase, we hypothesize that the shortcoming of current prolapse meshes is that they are too stiff. While this results in a repair with increased tensile strength, it occurs at the expense of tissue function with accelerated tissue contraction, decreased elasticity and compliance, and deterioration of smooth muscle function. To test our hypothesis, we implant commonly used synthetic prolapse meshes into the vagina of nonhuman primates with prolapse using the gold standard surgical procedure (the abdominal sacrocolpopexy) and then define the cellular, biochemical and biomechanical impact on the vagina at 6 months post implantation. Eventually, we will implant meshes transvaginally to characterize the distinct host response to this surgical approach. In the third phase, we explore the development of future grafts for prolapse surgery. We hypothesize that because of its bioinductive effects, a combined biologic/synthetic mesh will be superior to a synthetic mesh alone in restoring vaginal structure and function. We propose that a key yet poorly developed component of prolapse repairs is the re-establishment of smooth muscle reactivity and therefore, test the use of a temporary biologically active scaffold in achieving this process. In this way, this grant proposal provides a mechanism to establish the first team of scientists dedicated to the comprehensive unbiased evaluation of prolapse meshes as a means of educating both current and future prolapse surgeons, and the public regarding potential problems associated with certain materials. Indeed, the development of such a group is imperative for protecting the health of women. PUBLIC HEALTH RELEVANCE: Prolapse (i.e., abnormal descent) of the pelvic organs is a common costly condition that negatively impacts the lives of millions of women world-wide. Biologic and synthetic meshes are often used in the surgical repair of prolapse due to improved anatomical outcomes over native tissue repairs;but with little scientific data on which to base the selection of a particular product. Unfortunately, the complications associated with certain meshes cause unacceptably high rates of morbidity including infection, tissue contraction, vaginal discharge, and pain. In this proposal, we aim to establish a comprehensive mesh testing center in which previously or newly marketed prolapse meshes can be objectively tested and the next generation of prolapse meshes can be developed based on specific scientific criteria.